1. Field of the Invention
The present invention relates generally to tools of the type employed to smooth an optical surface.
2. Description of the Prior Art
Here, in the usual way, the term xe2x80x9csmoothingxe2x80x9d means both polishing and buffing a surface.
The tools employed for such smoothing generally include a rigid support and a working member fastened to the support. This is the case in particular with tools for smoothing ophthalmic lenses.
The present invention more particularly addresses the situation in which this member is of generally annular form and is at least in part elastically deformable.
A smoothing tool including a working member of this kind is described in German utility model No. 298 03 158, for example.
Because of its annular shape, the dimensions and stiffness of the working member can be sufficient for it to procure the required smoothing effect, its central opening minimizing its overall volume and therefore the quantity of elastically deformable material that actually has to be deformed.
This compromise is all the more advantageous in that, in practice, the active portion of a working member of this kind, i.e. the portion of the working member which does the most work, is its peripheral potion when, as here, the working member is rotated about its axis in use.
The elastically deformable portion of the working member advantageously enables it to adapt as closely as possible to the surface to be smoothed, with optimum equilibrium of the corresponding contact pressure.
A general object of the present invention is an arrangement offering improved control of the working member.
To be more precise, the present invention provides a tool for smoothing optical surfaces including a rigid support and a generally annular working member which is at least in part axially deformable, wherein the support forms a recessed annular housing and the working member is attached to the support via the bottom of the annular housing but projects beyond the support.
In other words, by virtue of the annular housing that it includes to receive it, the support surrounds the root portion of the working member and is therefore able to hold and guide the working member, which is to the benefit of its working conditions.
Furthermore, by channeling the swelling of the elastically deformable part of the working member which is inevitable in use, the support facilitates obtaining a uniform distribution of the contact pressure between the working member and the worked optical surface.
To accommodate this swelling as much as possible, at least one relief groove is preferably provided on at least one lateral surface of the annular housing of the support according to the invention.
Thus an advantageous compromise is also achieved between, on the one hand, the required holding and guiding of the working member and, on the other hand, the volume available to receive the part, despite any deformation thereof.